What question did this study set out to answer?

The aim is to compare electrical performance and clinical outcomes of various pacing modes in ATTR-CM patients.

March 30, 2026Open Access

Indication and electrical performance of conventional, resynchronisation and conduction system pacing in Transthyretin amyloid cardiomyopathy

Key Result

Conduction system pacing in ATTR-CM yielded significantly narrower QRS duration (122ms) and lower capture thresholds (0.75V) compared to CRT (155ms, 1.3V) and conventional pacing (160ms).

Key Points

The aim is to compare electrical performance and clinical outcomes of various pacing modes in ATTR-CM patients.
Conducted an observational study with 250 consecutive ATTR-CM patients.
Investigated the effects of conventional, resynchronisation, and conduction system pacing.
Analyzed patient outcomes over follow-up from June 2019 to February 2023.
26.8% of patients received a pacemaker during follow-up.
Lower QRS duration observed with conduction system pacing compared to other methods.
Patients with conduction system pacing had lower capture thresholds but no significant differences in lead performance during follow-up.

Structured PICO

Does conduction system pacing or cardiac resynchronization therapy improve electrical performance and clinical outcomes compared to conventional pacing in patients with transthyretin amyloid cardiomyopathy?

Population

67 patients with transthyretin amyloid cardiomyopathy (ATTR-CM) who received a pacemaker (out of a cohort of 250 consecutive ATTR-CM patients), predominantly male (94%), median age ~81 years, at a single center in Switzerland.

Intervention

Conduction system pacing (CSP) (n=18) or Cardiac resynchronization therapy (CRT) (n=14)

Comparator

Conventional single- or dual-chamber pacing (VVI/DDD) (n=35)

Outcome

Electrical performance (QRS duration, pacing capture thresholds, lead performance) and clinical outcomes (mortality, heart failure hospitalizations)

Conduction system pacing in ATTR-CM patients provides superior electrical resynchronization with shorter paced QRS durations and low capture thresholds compared to conventional and CRT pacing, though its impact on long-term clinical outcomes requires further study.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

Background:Conduction system disorders and arrhythmias may require pacemaker or ICD implantation in transthyretin amyloid cardiomyopathy (ATTR-CM).The optimal mode of pacing in ATTR-CM remains unknown.Objective: To compare electrical performance and clinical outcomes of conventional, resynchronisation and conduction system pacing in ATTR-CM. Methods:In this observational study, the effects of cardiac pacing were investigated in 250 consecutive ATTR-CM patients presenting at Inselspital Bern between June 2019 and February 2023.Results: During follow-up, 67 of 250 patients (26.8%) received a pacemaker.Implantation of conventional single-or dual-chamber (VVI/DDD) pacemakers was more common before ATTR-CM diagnosis (n=17/25; 68%), physiological pacing (CRT/CSP) was increasingly utilized thereafter n=24/42 (57.1%).Sick sinus syndrome n=11/35 (31.4%) vs. 6/32 (18.8% and higherdegree AV-block n=20/35 (57.1%) vs. 9/32 (28.1%) were more common indications for VVI/DDD, with pursuit of a pace/ablate strategy n=12/32 (37.5%) and heart failure n=5/32 (15.6%) contributing significantly to implantation of CRT/CSP.QRS duration width was significantly lower with CSP 122ms (IQR:120-139), compared to CRT 155ms (IQR:141-160) or VVI/DDD [160ms (IQR:144-180), p0.05).Patients referred for CRT/CSP had a higher incidence of heart failure (p=0.014) and more common heart failure hospitalizations (p=0.03),however, mortality was not significantly different (p=0.28). Conclusions:Offering stable electrical performance and improved resynchronization, the effect of conduction system pacing on clinical outcomes warrants further exploration in ATTR-CM.

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